Lesson Title: Mole-Volume Relationships and the Mole Road Map
State Standards: GLEs/GSEs
PS2 (Ext)-6
Students demonstrate an understanding of physical, chemical, and nuclear changes by... 6aa-using chemical equations and information about molar masses to predict quantitatively the masses of reactants and products in chemical reactions.
National Standards:
Context of Lesson:
Students will complete Part I of the laboratory exercise if they have not already done so. They will then be presented with the final conversion factor associated with the mole, volume. Students will explore this concept by practicing problems and making connections to previous material (density). The lesson will be concluded with the concept of the "mole road map" with will review all of the conversions associated with the mole. Lesson duration: 90 minutes.
Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Students will need to be familiar with the following:
Density
Mole-mass relationships
How many representative particles are in one mole
Plans for Differentiating Instruction
To strengthen both math and language skills have students write out the conversions without any numbers just the labels so students can better see the path of the conversion. You wrote this for you last lesson. When do you plan to do this? What will you say so that students understand what you're trying to demonstrate by this?
Accommodations and modifications
Environmental factors
There is a smartboard in the front of the room which will be ideal for working problems and practice examples. Desks are set up in rows.
Materials
Materials required for Part I of the laboratory exercise (dependent on whether or not it was completed in the last class)
Students will need their notebooks and calculators
2 liter soda bottle Why just one?
Objectives:
Students will use the mole to convert among measurements of mass, volume, and number of particles.
Instruction:
Opening:
To begin this lesson pose the following questions to the students:
What are the units used to determine the mass of a mole? Answer: grams/mole
What are the units that should be used to describe the volume of a mole? Answer: mL/mole or L/mole
How does temperature affect the volume of a gas? Answer: if temperature is increased particles move faster and take up more space (the opposite is true if the temperature is decreased). Will you answer these questions here are let them hang? Can you use the simulation to give students a change to formulate answers based on observations?
How does pressure affect the volume of a gas? Answer: if pressure is increased particles are pushed closer together and the volume is decreased (the opposite is true if the pressure is decreased). See above comments. Answers they you provide verbally are of low value compared to ones that students think they "figure out" on their own.
Explain to students that because of the fact that the volume of a gas is affected by temperature and pressure we must measure gases at STP (standard temperature and pressure), standard temperature being: 0 degrees Celsius and standard pressure being: 1 atm or 101.3 kPa
Engagement:
Now give the students the conversion factor: At STP one mole of any gas occupies a volume of 22.4 L. This quantity is known as the molar volume of a gas. To give them an idea of how big 22.4 L is do the following:
Show them the 2 liter soda bottle
Explain that 11 soda bottles = 22 L Why not have enough bottles for each class to construct a molar volume of gas by duct-taping bottles together? These next day, you could ask each class how many moles of gas are contained in the three clumps/arrays of bottles.
So, we would need 11.2 soda bottles to equal the molar volume of a gas They could bring in these bottles in the days leading up to the unit.
So, we've established that 1 mol = 22.4 L of any gas at STP. Thus, we can say that 22.4 L of any gas at STP contains 6.02x10^23 representative particles of that gas.
Note that it is two different things to be able to explain the effect of temperature on a gas's volume and pressure and to be able to relate these ideas to particle motion. Shouldn't you address both of these ideas here? If so, you should add what you want students to be able to do to your objectives.
Let's try some examples. If I wanted to determine the volume, in liters, of 0.60 mol of SO2 gas at STP I would do the following steps:
First, we must determine our path: we are going from moles to liters
Second, we set up our linear conversion and solve: 0.60 mol SO2 x 22.4 L SO2/1 mol SO2 = 13.44 = 13 L SO2
Assign the following practice problems:
What is the volume at STP of these gases?
3.20x10^-3 mol CO2
0.960 mol CH4
3.70 mol N2
If students are having trouble starting the problem give them this hint: Remember we are going from moles to liters.
Assuming STP, how many moles are in these volumes?
67.2 L SO2
0.880 L He
1.00x10^3 L C2H6
Now incorporate density into the lesson by doing the following:
Are you going to explain why you are introducing density? I think of density as a characteristic property of substances, but here it seems like just another calculation that is easily confused with others you have introduced.
Ask students: How do we measure density? Answer: D=M/V
Explain that the density of a gas is generally measured in g (mass)/L (volume)
Give the following practice example: The density of a gaseous compound containing Carbon and Oxygen is 1.964 g/L at STP. Determine the molar mass of the compound.
Ask students what units they are starting with and what units they should be ending with. Answers: Start with g/L, end with g/mol
Ask them: How will we set up the linear conversion? Answer: 1.964g/1L x 22.4L/1 mol = 44.0 g/mol
Assign students the following problem:
What is the density of Krypton gas at STP? (If students become stuck, ask them what units we are starting with and ending up with. Remind them of where to find the molar mass of Krypton if necessary)
Will students present their calculations? What feedback will you give them?
Closure:
We have now examined the mole in terms of particles, mass, and volume at STP. Explain to students that to convert from one unit to another, i.e. mass to volume, we use the mole as an intermediate step. Use the diagram on p. 186 of their textbook to demonstrate this. If time permits use problems from section review 7.2 that will not be assigned for homework for further examples.
Assessment:
Assign the following problems from section review 7.2 p. 186 for homework: 24 a,c; 25 a,b; 28. This assignment will be collected, corrected, and handed back. Each problem will be gone over during the class period which the assignment is handed back with ample time for questions.
Well specified lesson. Remember to think about having the students engage in two or three defined activities during a 90 minute period. Your transitions between your activities are not explicit. You should say: We just . Now we're going to __ so that students will see the transitions.
Lesson Plan
Lesson Title: Mole-Volume Relationships and the Mole Road Map
State Standards: GLEs/GSEs
PS2 (Ext)-6Students demonstrate an understanding of physical, chemical, and nuclear changes by...
6aa-using chemical equations and information about molar masses to predict quantitatively the masses of reactants and products in chemical reactions.
National Standards:
Context of Lesson:
Students will complete Part I of the laboratory exercise if they have not already done so. They will then be presented with the final conversion factor associated with the mole, volume. Students will explore this concept by practicing problems and making connections to previous material (density). The lesson will be concluded with the concept of the "mole road map" with will review all of the conversions associated with the mole. Lesson duration: 90 minutes.Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Students will need to be familiar with the following:Plans for Differentiating Instruction
To strengthen both math and language skills have students write out the conversions without any numbers just the labels so students can better see the path of the conversion. You wrote this for you last lesson. When do you plan to do this? What will you say so that students understand what you're trying to demonstrate by this?Accommodations and modifications
Environmental factors
There is a smartboard in the front of the room which will be ideal for working problems and practice examples. Desks are set up in rows.Materials
Objectives:
Instruction:
Opening:
To begin this lesson pose the following questions to the students:- What are the units used to determine the mass of a mole? Answer: grams/mole
- What are the units that should be used to describe the volume of a mole? Answer: mL/mole or L/mole
- How does temperature affect the volume of a gas? Answer: if temperature is increased particles move faster and take up more space (the opposite is true if the temperature is decreased). Will you answer these questions here are let them hang? Can you use the simulation to give students a change to formulate answers based on observations?
- How does pressure affect the volume of a gas? Answer: if pressure is increased particles are pushed closer together and the volume is decreased (the opposite is true if the pressure is decreased). See above comments. Answers they you provide verbally are of low value compared to ones that students think they "figure out" on their own.
The following website contains a simulation (must download first) which visually demonstrates the affects of temperature and pressure on a gas:http://phet.colorado.edu/simulations/sims.php?sim=Gas_Properties
Explain to students that because of the fact that the volume of a gas is affected by temperature and pressure we must measure gases at STP (standard temperature and pressure), standard temperature being: 0 degrees Celsius and standard pressure being: 1 atm or 101.3 kPa
Engagement:
Now give the students the conversion factor: At STP one mole of any gas occupies a volume of 22.4 L. This quantity is known as the molar volume of a gas. To give them an idea of how big 22.4 L is do the following:- Show them the 2 liter soda bottle
- Explain that 11 soda bottles = 22 L Why not have enough bottles for each class to construct a molar volume of gas by duct-taping bottles together? These next day, you could ask each class how many moles of gas are contained in the three clumps/arrays of bottles.
- So, we would need 11.2 soda bottles to equal the molar volume of a gas They could bring in these bottles in the days leading up to the unit.
So, we've established that 1 mol = 22.4 L of any gas at STP. Thus, we can say that 22.4 L of any gas at STP contains 6.02x10^23 representative particles of that gas.Note that it is two different things to be able to explain the effect of temperature on a gas's volume and pressure and to be able to relate these ideas to particle motion. Shouldn't you address both of these ideas here? If so, you should add what you want students to be able to do to your objectives.
Let's try some examples. If I wanted to determine the volume, in liters, of 0.60 mol of SO2 gas at STP I would do the following steps:
- First, we must determine our path: we are going from moles to liters
- Second, we set up our linear conversion and solve: 0.60 mol SO2 x 22.4 L SO2/1 mol SO2 = 13.44 = 13 L SO2
Assign the following practice problems:What is the volume at STP of these gases?
- 3.20x10^-3 mol CO2
- 0.960 mol CH4
- 3.70 mol N2
If students are having trouble starting the problem give them this hint: Remember we are going from moles to liters.Assuming STP, how many moles are in these volumes?
- 67.2 L SO2
- 0.880 L He
- 1.00x10^3 L C2H6
Now incorporate density into the lesson by doing the following:Are you going to explain why you are introducing density? I think of density as a characteristic property of substances, but here it seems like just another calculation that is easily confused with others you have introduced.
- Ask students: How do we measure density? Answer: D=M/V
- Explain that the density of a gas is generally measured in g (mass)/L (volume)
- Give the following practice example: The density of a gaseous compound containing Carbon and Oxygen is 1.964 g/L at STP. Determine the molar mass of the compound.
Ask students what units they are starting with and what units they should be ending with. Answers: Start with g/L, end with g/molAsk them: How will we set up the linear conversion? Answer: 1.964g/1L x 22.4L/1 mol = 44.0 g/mol
Assign students the following problem:
What is the density of Krypton gas at STP? (If students become stuck, ask them what units we are starting with and ending up with. Remind them of where to find the molar mass of Krypton if necessary)
Will students present their calculations? What feedback will you give them?
Closure:
We have now examined the mole in terms of particles, mass, and volume at STP. Explain to students that to convert from one unit to another, i.e. mass to volume, we use the mole as an intermediate step. Use the diagram on p. 186 of their textbook to demonstrate this. If time permits use problems from section review 7.2 that will not be assigned for homework for further examples.Assessment:
Assign the following problems from section review 7.2 p. 186 for homework: 24 a,c; 25 a,b; 28. This assignment will be collected, corrected, and handed back. Each problem will be gone over during the class period which the assignment is handed back with ample time for questions.Well specified lesson. Remember to think about having the students engage in two or three defined activities during a 90 minute period. Your transitions between your activities are not explicit. You should say: We just . Now we're going to __ so that students will see the transitions.
Reflections
(only done after lesson is enacted)Student Work Sample 1 – Approaching Proficiency:
Student Work Sample 2 – Proficient:
Student Work Sample 3 – Exceeds Proficiency: